Internal-combustion engine with counterrunning pistons



Nov. 20, 1928. 1,692,499

J. G. GRONVALL INTERNAL COMBUSTION ENGINE WITH COUNT Original Filed Nov. 2. 1920 ERRUNNING PI STONS 7 piston may compress Patented Nov. 20, 1928.

PATENT OFFICE.

JOHN G. GRGNVALL, OF STOCKHOLM, SWEDEN.

INTERN All-COMBUSTION ENGINE WITH COUNTERRUNNING PISTONS.

Application filed November 2, 1920, Serial No 421,344, and in Great Britain September 15, 1920. Renewed May 16, 1928.

The present invention relates to improvements in internal combustion engines having counterriuining pistonsand it is an object or the invention to provice an engine oi this character with concentrically arranged pistons whereby the explosions may take place in one piston, thus jointly exerting a force upon both pistons at the same time for giving increased power and owing to the low number of revolutions made by an engine of this character, it may work with economical adyantages, especially fitting the same for driving large ships and the like;

Other objects of the invention are set forth due to the fact that the explosions may take place in the opposite ends of one piston for exerting a force jointly upon both pistons in opposite directions'and one of said pistons acting as a slide valve for controlling the intake and exhaust gases.

A further object of the invention is to improve the construction of such engines whereby they may be easily and readily utilized as air motors or compressors and still further, one in which the starting and reversing of the engine may be easily and readily accomplished by the injection of compressed air within the cylinder thereof.

l/Vith the above and'other objects in view, the invention consists of a single cylinder or multiple cylinders each having a sliding piston therein which acts as a slide valve for controlling the inlet and outlet gases. Concentrically arranged within this sliding piston,.is an auxiliary piston which acts in an opposite direction to the. first mentioned piston, so that when the explosions take place within the opposite ends of the first mentioned piston, theforces ofsmh explosions will act jointly upon both the pistonsso as to cause them to move in opposite directions. The cylinder of this internal combustion engine is relatively long so that the outermost air thereon or compressedairmaybeinjectedthereinforexerting a force upon said piston whereby the engine may be utilized as a compressed air engine or air pump. The invention further consists of means for permitting compressed air to 'be injected tliereinto which may act upon the outermost piston, whereby the engine'may be started or reversed, atlwill, and other com bination, formation and arrangement of parts as will be hereinafter more fully deto be understood that are connected to the scribed and particularly pointed out in the appended claims.

In the accompanying drawing, I have illustrated schematically a central longitudinal section of a cylinder preferably of a vertical marine oil enginemade inaccordance with thisinvention. I v

Referring now more particularly to the accompanying drawing, wherein like and corresponding lar reference characters throughout, I have illustrated a single cylinder having counterrunning pistons therein, but of course, it is any number of cylinparts are designated by simiders may be employed, according to the' nature of the engine preferably utilizes sion ignition. v The cylinder 5,'as herein shown, is relativelylong and has an outer piston 1 slidably, arranged therein. Ooncentrically arranged and slidably within the piston '1 is an auxiliary piston 2 having connected thereto a piston rod 19 which is slidably mounted within the hollow piston rod 18 connected to the outer piston 1. This piston rod 19 is connected to a rod 21 which is adapted to drive the crank 23 of the driven shaft, whereas the cranks 22 ofthis driven shaft piston rod 18 by means of the connecting rod 20. These pistons of course operate in opposite directions so as to transmit a rotary motion to the driven shaft through the connecting rods 19 and 20 as herein described. The outer piston 1 is hollow so that a cooling agent such as water may circulate therethrough and this water is supplied to the hollow piston, through the pipe 16, which latter extends throughone end of the cylinder 5 and exhausts through the pipe 17 which extends through the oppo site end of the cylinder 5. It is of course understood that the piping 16 and 17 may slide within suitable packing bearings arranged within the cylinder 5 and may be connected to a suitable source of water supply whereby the water or other cooling agent may be circulated through the piston 1 while the latter is in motion'. This outer piston 1 is provided intermediate of its length with a ring of exhaust ports 3, whereas its opposite ends are each provided with a ring of the scavenging air ports 4. The diametrically opposite exhaust ports 4 of eachringare and that each cylinder liquid fuel and compresarranged in the same plane, whereas the remaining scavenging air ports of each ring are arranged in different planes as is clearly illustrated in the drawings, for a purpose which will be later described. The cylinder 5 is provided with con'imunicating exhaust ports 6 and 7 which are adapted to communicate with the exhaust ports 3 of the piston 1. Arranged on each side of the exhaust ports and within the cylinder 5 are the fuel injecting valves and combination spark plugs 11. These valves 11 are arranged in pairs and are adapted to communicate with the ports a of the piston 1 whereby the explosive fuel may be supplied within the opposite ends of the piston 1.

Encircling the opposite ends of the cylinder 1 are the air storage chambers 13 which communicate with the interior of the cylinder by means of the scavenging ports 8 and the air aftercharging ports 9, the latter ports being controlled by the valves 10 which are adapted to be opened and closed by means of a suitable timing mechanism, not shown.

From the above construction, that the piston 1 slides in the upper and lower explosive chambers so that when an explosion takes place in either end of this piston, both of the pistons will be driven in opposite directions. The two pistons are shown in the accompanying drawing when about to complete their compression strokes in the upper explosive chamber and when in this position, the fuel will be brought into this upper chamber from the fuel injecting valve 11 arranged upon the upper end of the cylinder 5 and this fuel will be admitted into the piston 1 through the upper port 4 situated adjacent to the injecting port 11. At the same time, the lower explosive chamber of the piston 1 is cleaned as the scavenging ports 8, 8 and the exhaust ports 7 are in communication due to the fact that one set of exhaust ports 1 within the lower end of the piston 1 are in communication with the ports 8, whereas the rings of the exhaust port 3 are in communication with the ports 7 and the air drawn within the chamber 13 is permitted to travel through the lower explosive chamber of the piston 1 and exhaust through the port 7 thereby thoroughly cleaning the lower explosive chamber. This latter operation, of course, occurs within each explosive chamber so as to thoroughly cleanse the same after each explosion. When the explosion takes place within the upper chamber, the pistons are forced in opposite directions whereby the lower ends of the pistons will move towards one another and the ports 7 and 8 arranged in the lower ends of the cylinder are closed. Immediately after the closing of the port 7, the valves 10 begin to move so that the ports 9 will be opened and when one set of the portsl in the lower end of the piston 1 communicate with the it is obvous 7 ports 9, a supply of air from the chamber 13 will enter the lower explosive chamber. As soon as the ports a pass the ports 9, and the latter are closed, the compression stroke of tnc engine starts within the lower explosive chamber. As the piston 1 moves upwardly, one set of the ports-a will come into communication with the fuel inlet ports 11 whereby a charge of explosive fuel will be injected into the lower explosive chamber and commingle with the compressed air contained therein. This mixture of explosive fuel and air within the lower explosive chamber is also compressed and at the end of this compressing stroke, this mixture is exploded, thereby forcing the pistons in opposite directions, or in other words, forcing the piston 1 in a downward direction and the piston 2 in an upwardly direction until the ports 3 again communicate with the ports 7 whereby the exhaust gases may escape from the lower explosive chamber. The ports 4: arranged in the upper end of the piston 1 are of course adapted to communicate with the ports 8 and 9 in a similar manner to that explained above in reference to the ports in the lower end of the piston 1 of the cylinder 5' so that the aftercharging of air and explosive gases may be admitted into the upper explosive chamber so that an explosion may take place within this upper chamber. The exhaust gases contained within the upper explosive chamber as well as the compressed air used for scavenging this upper explosive chamber pass through the ports 3 within the piston 1 but exhaust through the ports 6, otherwise the operation and explosion takes place within the upper explosive chamber in the same manner as described within the lower explosive chamber of the piston.

The opposite ends of the cylinder 1 are provided with the chambers 12 in which are adapted to operate the ends of the piston 1 and communicating with the respective chambers 12 are the air inlet ports 15. The cylinder heads are provided with pressure air outlet valves 1 1- and these latter valves are also in communication with the chambers 13. When the outer piston 1 is in a position as shown in the vdrawings, atmospheric air may be drawn in through the ports 15 into the upper chamber 12 and upon the upward stroke of this piston 1, this air will be compressed and forced through the pressure air outlet valves 1 1, whereby the compressed air maybe transmitted to a suitable storage tank or conveyed to do other work. A portion of this air passes from the air outlet valves 14: to the storage chamber 13 so that it may be utilized for cleaning the explosive chambers or to commingle with the explosive gases within the piston 1.

It is to be also understood that the compressed air may be admitted into the chamber 12 through the valves 1 1 where it will ill) exhaust ports of 1,692,499 I s I 3 act upon the opposite ends of the piston l and then escape through the opening 15 when the motor is utilized as an air pump.

A starting valve 24. is placed in each head of the cylinder whereby; compressed air may be injected within the chamber-s12 :for forcing the piston 1 in opposite'directions. This starting valve affords ample means for starting the engine, or it may be also utilizedfor reversing the engine. It is of course to be further understood that the valves 10, 11 and 14 may be suitably controlled by a timing mechanism whereas the valve 24 maybe manually controlled for starting or reversing the engine. i

It of course is to be further understood that the cylinder 5 may have suitable encirclingchambers whereby a cooling agent may be passed thcre'through. The chambers for receiving this cooling agent are preferably arran ed between the points within the lines indicated by the letter L but these water cooling chambers may be arranged at any point upon the cylinder to meet the requirements thereof. I a v Manifestly, the construction shown is capable of considerable modification and such modification as is within the scope of my claims, I consider within the spirit of my invention.

I claim:

1. A double acting two cycle internal combustion engine comprising a'cylinder having a ring of exhaust ports arranged in the medial portion thereof, a hollow piston mounted to reciprocate in said cylinder, said hollow piston having a central ring of exhaust ports adapted to communicateiwith the said cylinder, and a ring of inlet ports arranged adjacent each end thereof, said cylinder having air scavenging, air after charging and explosive fuel ports arranged in each end thereof adapted to communicate directly with the rings of inlet ports arranger at the opposite end of the hollow piston, and a piston reciprocating in said hollow piston forming combustion chambers therein, substantially as for the purpose specified.

2. A double acting two cycle internal combustion engine comprising a cylinder having rings of air scavenging and exhaust ports, a hollow piston mounted to reciprocate in said cylinder, said hollow piston having a central ring of exhaust ports adapted to communicatc with the exhaust ports of said cylinder, and a ring of inlet ports arranged in each end thereof, said cylinder having fuel valves, and the air scavenging ports arranged in each end thereof adapted to com municate directly with the inlet ports of said hollow piston, an. inner piston reciprocating in said hollow piston forming combustion chambers therein, the opposite sides of said inner piston adapted to be positioned level with the homological sides of the exhaust portsoof av corresponding ring hollow piston when said air. scavenging ports'and inletxports wholly communicate with each other, substantially as and for. the purpose described. V

3. A double actingtwo-cycle internal comustion engine comprisingna' cylinder having rings of air-scavenging and exhaust ports, a hollow piston mounted to reciprocate in said cylinder, said hollow piston having a ccntral=ring of exhaust ports adapted to communicate with the exhaust portsof said i c rlinder' and a rin of inlet oort's arran ed a a; l r a in each end thereof, said cylinder having fuel valves and the air scavenging ports arranged in respective ends thereof adapted to communicate directly with the inlet ports of said. hollow piston, an inner piston reciprocating in saidhollow piston forming combustion chambers therein, said inner piston having its respective power sides adjacent to homologicaly sides of the exhaust portsof said hollow piston, when a corresponding ring of air scavenging ports and lnlet ports wholly communicate with each other, substantially as and for the purpose described. I

it. A double acting two cycle internal combustion engine comprising a cylinder having air scavenging and exhaust ports, a hollow piston mounted to reciprocate in said cylin der, a piston reciprocating in said hollow piston forming combustion chambers therein,

said hollow piston having inlet and exhaust ports communicating with the air scavenging and exhaust ports of said cylinder, said cylinder having air after charging ports adapted to communicate with the inlet ports of said'hollow piston,

5. Afdouble acting two cycle internal combustion engine comprising a cylinder having air scavenging and exhaust ports, a hollow piston mounted to reciprocate in said cylinder and forming air chambers in both ends of the cylinder, a piston reciprocating in,

said hollow piston forming combustion chambers therein, air storage chambers arranged at both ends of said cylinder communicating with said air and combustion chambers, and said hollow piston having inlet and exhaust ports communicating with air scavenging and exhaust ports of said cylinder.

6. A double acting two cycle internal combustion engine comprising a cylinder having air scavenging and exhaust ports, a hollow piston mounted to reciprocate in said cylinder and forming air chamber in the farthest from the engine frame situated end of the cylinder, a piston reciprocating in said hollow, piston forming combustion chambers therein, air storage chambers arranged at both ends of said cylindercommunicating with said air and combustion chambers, said hollow piston having inlet and exhaust ports communicating with air scavenging and exhaust ports of said cylinder.

7 A double acting two cycle internal combustion engine comprising a cylinder having air scavenging and exhaust ports, a hollow pistonmounted to reciprocate in said cylinder and forming air chamber in the farthest from the engine frame situated end of the cylinder, a piston reciprocating in said hollow piston forming combustion chambers therein, said hollow piston having inlet and exhaust ports communicating with air scavenging and exhaust ports of said cylinder, said air chamber provided with starting valves and air outlet organs adapted to start the engine in desired direction of movement.

8. A double acting two cycle internal com bustion engine comprising acylinder having air scavenging and exhaust ports, a hollow piston mounted to reciprocate in said cylinder, a piston reciprocating in said hollow piston forming combustion chambers therein, said hollow piston having inlet and exhaust ports communicating with the air scavenging and exhaust ports of said cylinder, said cylinder provided with starting inlet valves situated in similar manner as the fuel valves so that starting air through said inlet ports can be laid on said combustion chambers, adapted to start the engine in desired direction of movement, short canals cutin the cylindrical walls and going from said inlet organs in such a direction that the full pressure ratio of the starting period is enlarged. i

In testimony that I claim the foregoing as my invention I have signed my name.

JOHN G. GRCNVALL. 

